More Women, Especially Younger Ones, Are Smoking Weed While Pregnant

Even though a lot of doctors say it’s a bad idea.

Recreational pot is officially legal in California—hooray for you West Coast ganja gluttons! According to the law, Californians can possess as much as an ounce and grow up to six plants at home. But while anyone 21 and older can now (theoretically, anyway) toke up without fear of being fined or going to jail, the question is, should they?

According to a new study published in the Journal of the American Medical Association in December, an increasing number of pregnant women, especially younger ones, are using marijuana.

In order to get a better idea of how many women continue to blaze up after they get knocked up, researchers analyzed the survey responses and toxicology reports of more than 275,000 pregnant women who were being treated at one of the facilities in the the Kaiser Permanente Northern California health system. The sample covered women who were getting prenatal care during the first two months of their pregnancy between 2009 and 2016.

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Overall, the study found that marijuana use increased from 4 percent to 7 percent over the study period. Unsurprisingly, use among women younger than 18 at the time and for those who were between 18 to 24 years increased the most, from 12.5 percent to 22 percent.

Of course, there were some limitations to the study, in that it only screened women in California. (Imagine what the research might look like if they included people in Colorado and Washington, which legalized recreational weed six years ago.) It was also unclear whether the respondents knew they were pregnant when they lit up, since marijuana is detected up to approximately 30 days after last use. “It is possible, but unlikely, that some toxicology tests identified prepregnancy use,” the study’s authors write.

Kelly C. Young-Wolff is a licensed clinical psychologist and research scientist at the Kaiser Permanente Northern California Division of Research and lead author of the study. She notes that “perceived approval of marijuana use is increasing and perceived risk of marijuana use is decreasing, particularly among young people.”

In fact, during a recent episode of NPR’s "Morning Edition," a 21-year-old mother admitted that she used marijuana the entire time she was pregnant with her first kid. Recounting a conversation with her doctors during which she defended her use, she said, “I was like, 'Test me!' I was like, 'Observe me. My kid could count to 10 before she was even 2 by herself, and I smoked pot throughout my whole pregnancy. She's not stupid! There is no third eye growing.’"

But Young-Wolff says we need way more research to get a better understanding of the health impacts of prenatal marijuana use. For this reason, the American Congress of Obstetricians and Gynecologists—the premier professional medical association dedicated to women’s health—recommends pregnant women or even those just thinking about having a kid should put away their pipes.

“Sufficient evidence points to an association between prenatal marijuana use and lower birth weight, and limited research shows a correlation with some developmental delays or difficulties with executive functioning in the child (e.g., problems with impulse control, and attention during school years),” Young-Wolff says. “But data on other potential side effects and health risks are limited by the number and quality of existing studies.”

We also still don’t know why more pregnant women are using marijuana, she continues, and that’s definitely another area that needs to be studied.